<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>后盾人</title>
  </head>
  <body>
    <script>
      let number = 0;
      // console.log(typeof number);
      // number = !!number;
      // console.log(number);
      // console.log(Boolean(number));

      let string = "houdunren";
      // console.log(!!string);
      // console.log(Boolean(string));

      let array = [];
      // console.log(!![]);
      // console.log(Boolean([]));

      let object = {};
      // console.log(!!{});
      // console.log(Boolean(object));

      let date = new Date();
      console.log(!!date);
      console.log(Boolean(date));
    </script>
  </body>
</html>
